Interactions with titin and myomesin target obscurin and obscurin-like 1 to the M-band: implications for hereditary myopathies

Atsushi Fukuzawa, Stephan Lange, Mark Holt, Anna Vihola, Virginie Carmignac, Ana Ferreiro, Bjarne Udd, Mathias Gautel

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu


Obscurin, a giant modular muscle protein implicated in G-protein and protein-kinase signalling, can localize to both sarcomeric Z-disks and M-bands. Interaction of obscurin with the Z-disk is mediated by Z-disk titin. Here, we unravel the molecular basis for the unusual localization of obscurin, a Z-disk-associated protein, to the M-band, where its invertebrate analogue UNC-89 is also localized. The first three domains of the N-terminus of obscurin bind to the most C-terminal domain of M-band titin, as well as to the M-band protein myomesin. Both proteins also interact with the N-terminal domains of obscurin-like 1 (Obsl1), a small homologue of obscurin. Downregulation of myomesin by siRNA interference disrupts obscurin-M-band integration in neonatal cardiomyocytes, as does overexpression of the binding sites on either myomesin, obscurin or Obsl1. Furthermore, all titin mutations that have been linked to limb-girdle muscular dystrophy 2J (LGMD2J) or Salih myopathy weaken or abrogate titin-obscurin and titin-Obsl1 binding, and lead to obscurin mislocalization, suggesting that interference with the interaction of these proteins might be of pathogenic relevance for human disease.
LehtiJournal of Cell Science
NumeroPt 11
DOI - pysyväislinkit
TilaJulkaistu - 2008
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

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